Bluetooth LE HID keyboard randomly disconnects after upgrading from macOS 26 to macOS 27

After upgrading my M1 MacBook Pro from macOS 26 to macOS 27, my NuPhy Kick75 Bluetooth keyboard started randomly disconnecting during normal use.

This issue did not occur on macOS 26 with exactly the same Mac, keyboard, physical location, and usage environment.

The problem started immediately after upgrading to macOS 27.

The keyboard disconnects approximately 2–3 times per hour. When the interruption occurs, the Bluetooth connection indicator on the keyboard also shows that the Bluetooth link has been lost. This is therefore an actual Bluetooth disconnection rather than only input lag or delayed keyboard events.

The keyboard automatically reconnects shortly afterward.

macOS bluetoothd logs captured at the exact time of an occurrence confirm that the Bluetooth LE HID link is being disconnected.

Hardware

Mac: MacBook Pro with Apple M1

Keyboard: NuPhy Kick75

Bluetooth device name: Kick75 IO-2

Connection type: Bluetooth LE HID

Regression

macOS 26: No Bluetooth disconnections observed during long-term normal use.

macOS 27: Random Bluetooth disconnect/reconnect events occur approximately 2–3 times per hour.

No keyboard, firmware, physical location, or other hardware/environmental changes were made when the issue started. The behavioral change occurred immediately after upgrading the Mac from macOS 26 to macOS 27.

Steps to Reproduce

1. Connect a NuPhy Kick75 keyboard to an M1 MacBook Pro using Bluetooth.
2. Use the keyboard normally for typing.
3. Continue normal use for approximately one hour.
4. At seemingly random intervals, keyboard input suddenly stops.
5. At the same time, the keyboard's Bluetooth connection indicator shows that the Bluetooth link has been lost.
6. macOS automatically reconnects to the keyboard shortly afterward.
7. The same event can be observed in bluetoothd logs as an LE HID link disconnection.

Frequency

Intermittent but frequent.

Approximately 2–3 occurrences per hour after upgrading to macOS 27.

Expected Result

The Bluetooth LE HID connection should remain stable during normal use, as it did on macOS 26.

Actual Result

The Bluetooth LE HID connection is unexpectedly terminated. macOS subsequently reconnects to the keyboard automatically.

Relevant bluetoothd Log

The following was captured during an actual disconnection at:

2026-09-15 17:47:44

Disconnect OI_HCI_LM_HANDLE: 0x55 (85) wakeUp: No
RSSI: -37 -37 -37 -37 ...

_GATT_LE_DisconnectedCB ... reason STATUS 708

LE Link disconnected ... reason 708

LE ConnManager disconnection complete
reason 708
localRole=Central
encrypted:1

linkReady:1
disconnectDevice:0
localRole:0
reason:708
result:307

Device disconnected - {
    devicename: Kick75 IO-2,
    result: 307
}

App disconnected - {
    bundle: com.apple.BTLEServer,
    reconnecting: Y
}

macLeDeviceDisconnected:
LE Connection disconnected.
Device is a LE HID.

BLE Disconnected Unspecified
reason 708

Setting LeDevice to Compatible HID from Compatible HID

The RSSI values immediately before the disconnection remained consistently around -37 dBm, indicating a very strong Bluetooth signal at the time the link was lost.

The following fields appear consistently relevant to this event:

reason:708
result:307
disconnectDevice:0
reconnecting:Y

macOS also classified the keyboard as a Compatible HID.

Related Community Reports

This may not be isolated to the Kick75.

There is an independent community report involving a NuPhy Air75 V3 on macOS 27 that describes very similar Bluetooth LE HID disconnections.

That report has several notable similarities:

• The Air75 V3 disconnects repeatedly on macOS 27.

• The same keyboard reportedly operates normally on Windows and iOS 27.

• Other Bluetooth devices connected to the affected Mac reportedly remain stable.

• The reporter's macOS Bluetooth logs contain:

  • Incompatible LE HID
  • HID latency issue detected
  • LE Link disconnected (reason 708)

• Another user reported the same problem with a NuPhy Air65 V3.

• NuPhy Support responded that they had adjusted Bluetooth parameters and optimized the Bluetooth connection interval, and offered a test firmware for further investigation.

• The original reporter later tested the same Air75 V3 over Bluetooth on a Mac running macOS 26 at an Apple Store and reported that it did not disconnect.

• The reporter also observed that having certain Apple Bluetooth HID devices connected at the same time could affect the frequency of the NuPhy disconnections.

The community report is titled:

“Air75 V3 randomly disconnects on macOS 27 Developer Beta (works perfectly on Windows & iOS 27)”

I am including the link to that report with this feedback as supporting information.

Importantly, that report involves different NuPhy hardware and a different Mac, but its LE Link disconnected (reason 708) log message closely matches the reason 708 observed independently on my Kick75.

This suggests the issue may affect more than one NuPhy Bluetooth LE HID keyboard model under macOS 27.

Summary

My own reproducible observations are:

• Same M1 MacBook Pro
• Same NuPhy Kick75
• Same physical environment
• Stable Bluetooth operation on macOS 26
• Frequent disconnections immediately after upgrading to macOS 27
• Approximately 2–3 disconnections per hour
• Keyboard Bluetooth indicator confirms actual link loss
• bluetoothd confirms an LE HID disconnection
• RSSI was approximately -37 dBm immediately before the disconnection
• macOS records reason 708, result 307, and subsequently attempts to reconnect
• An independent NuPhy Air75 V3 report on macOS 27 also contains LE Link disconnected (reason 708)

Taken together, these observations suggest a possible Bluetooth LE HID compatibility regression introduced in macOS 27.

I can provide additional Bluetooth diagnostics, a sysdiagnose, and reproduce the issue with Apple's Bluetooth debug logging profile enabled if required.